Flatten each escalope slightly with a rolling pin between some plastic film. Cut slightly into skin edges every 2 cm. Spice with salt and pepper. Then coat in the flour. Make sure both sides are evenly coated. Heat oil in a frying pan, add the escalopes and fry on each side until lightly brown. Add the wine to the pan and and cook until reduced. Add gravy or beef stock. Simmer covered for 30 minutes until escalopes are completely through.
Transfer the escalopes to a warmed serving platter with a spatula, cover and keep warm. Add cream and bring it to the boil. Blend flour and sour cream well to make a paste, then add to the pan and stir to combine. Bring to the boil again and allow to simmer for 5 minutes. Stir in chopped parsley and season to taste with salt and freshly ground black pepper. Now add the escalopes and let them sit a little bit.